Photovoltaic cell tabs and method and system for forming same

Abstract

A photovoltaic cell tab including: a front contact portion having a first profile; and a back contact portion having a second profile, wherein the first profile or second profile are complex shapes that may be dissimilar to each other. A system and method for forming photovoltaic cell tabs comprising: a feeding mechanism to feed wire; a first forming tool to trim and shape the wire to tabs; and a placement tool configured to match a profile of the tabs and place and attach the tabs on photovoltaic cells. In the system and method, the tabs may be formed to have a complex profile or shape that will affect incident light and/or mechanical or other characteristics of the tabs.

What is claimed is: 
     
       1. A photovoltaic cell tab comprising:
 a front contact portion having a top surface and a bottom surface and a first profile; and 
 a back contact portion having a second profile, 
 wherein the first profile is formed such that the top surface is laterally folded under the bottom surface such that a top surface of the front contact portion is configured to contact a photovoltaic front contact and the profile provides an interior void. 
 
     
     
       2. A photovoltaic cell tab of  claim 1  wherein the first profile further comprises complex shapes intended to affect incident light in a predetermined manner. 
     
     
       3. A photovoltaic cell tab of  claim 1  wherein the first profile comprises angular facets configured to affect incident light in a predetermined manner. 
     
     
       4. A photovoltaic cell tab of  claim 3  wherein the angular facets are configured to reflect incident light obliquely. 
     
     
       5. A photovoltaic cell tab of  claim 3  wherein the angular facets are configured to reflect incident light such that it falls on active portions of the cell to produce photocurrent. 
     
     
       6. A photovoltaic cell tab of  claim 3  wherein the angular facets are configured to reduce the amount of incident light that is visibly reflected thereby making the tab less visible. 
     
     
       7. A photovoltaic cell tab of  claim 3  wherein the angular facets are configured as ridges and grooves in longitudinal, transverse or complex patterns. 
     
     
       8. A photovoltaic cell tab of  claim 1  wherein the second profile does not include angular facets. 
     
     
       9. A photovoltaic cell tab of  claim 1  wherein only one side of the tab is tinned. 
     
     
       10. A photovoltaic cell tab of  claim 9  wherein the tab is configured so that the tinned side of the tab makes contact with both the front contact area of one cell and the back contact area of another cell. 
     
     
       11. A photovoltaic cell tab of  claim 1  wherein at least a portion of the transverse width of the tab is tapered. 
     
     
       12. A photovoltaic cell tab of  claim 11  wherein the taper is provided to the transverse width of the front contact portion of the tab, the transverse width of the back contact portion of the tab, or both. 
     
     
       13. A photovoltaic cell tab of  claim 1  wherein the first profile is configured to increase the lateral stiffness of the tab. 
     
     
       14. A photovoltaic cell tab of  claim 1  wherein the second profile is configured to make the back contact portion of the tab thinner than the front contact portion. 
     
     
       15. A photovoltaic cell tab of  claim 1  wherein the second profile is configured to make the back contact portion appropriate for attachment by means of spot welding. 
     
     
       16. A photovoltaic cell tab of  claim 1  wherein the first profile or second profile are configured to provide transverse features to facilitate evacuation of air during a module lamination process.